A Minecraft-style voxel builder that exports valid input files for Fire Dynamics Simulator (FDS) — the world's most popular fire CFD tool. Designed to lure unsuspecting kids, students, and curious humans into fire engineering one block at a time.
▶ Play it now in your browser · ⬇ Download the latest release
You have two options. Both run the exact same code.
Click Play FDS Craft in your browser. Works on any modern desktop browser. Your scenes autosave to localStorage in that browser, so come back to the same machine and your build is still there.
Grab the latest release zip, unzip it anywhere (Desktop, Downloads, USB stick, school network share — wherever), and double-click index.html. That's the whole setup procedure. All assets are vendored locally; once you have the folder you can use FDS Craft on a plane, in a basement, behind a corporate firewall.
If you'd rather track development, clone instead: git clone https://github.com/ProfRino/fds_craft.git. Per-version download counts and older releases live at https://github.com/ProfRino/fds_craft/releases.
You place blocks. The app writes a &OBST for each one. You add a burner. The app writes &REAC and &SURF with sensible defaults. You hit Export, get a .fds file, drop it into FDS, and watch a polyurethane fire eat your scene.
It is, in fact, the gentlest possible on-ramp into a software ecosystem that normally welcomes new users with a 540-page user guide and a Fortran 90 stack trace.
- Click Start.
- Click in the canvas to lock the pointer.
- Build something with right-click. Add a burner. Hit Export.
That's it. If you want to host your own copy for a classroom, drop the folder on any static file server (GitHub Pages, Netlify, your nephew's Raspberry Pi).
| Action | Input |
|---|---|
| Move | W A S D |
| Fly up / down | Space / Shift |
| Sprint | Ctrl |
| Look | Mouse |
| Place block | Right-click |
| Break block | Left-click |
| Pick material | 1 – 7, or scroll wheel |
| Carve a HOLE | Pick HOLE, right-click any non-fire block |
| Pause / release pointer | Esc |
| Block | What you get in the .fds |
|---|---|
| Concrete | &OBST SURF_ID='CONCRETE' — inert wall, ρ = 2300, λ = 1.8 W/m·K |
| Wood | &OBST SURF_ID='WOOD' — ρ = 450, λ = 0.14 (no pyrolysis by default) |
| Steel | &OBST SURF_ID='STEEL' — non-combustible structural surface |
| Glass | &OBST SURF_ID='GLASS' — 30 % transparent in Smokeview |
| Burner | &OBST SURF_ID='BURNER' — HRRPUA = 500 kW/m², TAU_Q = -30 s t² ramp |
| Hole | &HOLE — overlays an existing non-fire block to carve an opening through it |
The HOLE rule mirrors how FDS works: &HOLE only does something when it overlaps an &OBST. So in this builder a HOLE is an overlay you paint onto a block, not a thing you place in empty space.
Exports also include:
- An auto-sized mesh with sensible padding so plumes have room to develop.
&REACfor polyurethane combustion (SFPE handbook defaults) when there's a burner.&VENT MB='OPEN'on five faces so the smoke can leave.- Diagnostic slices: temperature, visibility (with soot), and an HRRPUV plane through the burner.
- Greedy X-merging — a 10-block wall becomes 1 OBST line.
- Autosave — every 30 s to
localStorage, restored on next page load. - Save / Load — manual
.fdscraft.jsonfiles via the overlay menu, in case you want to share a scene or version-control it.
FDS Craft exports valid FDS syntax. That is the only promise.
Any resemblance to real fire dynamics is a happy accident. Please get a qualified fire engineer to check the .fds before showing it to a building consent officer (or to anyone whose insurance you care about).
No responsibility is taken for your kids becoming a fire engineer — or, even worse, a fire scientist.
| Library | Use |
|---|---|
| Three.js r128 | 3D rendering — vendor/three.min.js (MIT) |
| VT323 | Pixel body font — Peter Hull (OFL) |
| Press Start 2P | Pixel heading font — CodeMan38 (OFL) |
| Web Audio API | All sounds synthesised live — no samples used |
Block, fire, and smoke textures are generated procedurally at runtime in pure JS canvas, so the entire visual identity weighs less than a single PNG.
MIT — do whatever you like, but don't blame us when the burner exports correctly and your living-room model floods with simulated soot.
FDS and Smokeview are developed by NIST. This project has no affiliation with NIST — it's a fan project that just happens to speak their language.